Immunohistological findings in patients with superficial bladder carcinoma after intravesical instillation of keyhole limpet haemocyanin.

OBJECTIVE: To determine whether keyhole limpet haemocyanin (KLH) instilled intravesically improves the local cellular response within the bladder wall of patients suffering from superficial bladder carcinoma.

PATIENTS AND METHODS: Twelve patients (10 men and two women, mean age 67 years, range 42-85) with superficial carcinomas of the bladder were treated for 6 consecutive weeks and then monthly for 1 year with 20 mg KLH in 20 mL saline instilled intravesically after complete resection of the tumours. Biopsies were taken for immunohistochemical examination before treatment and again 6 weeks, 3, 6 and 9 months after treatment. Six patients with no evidence of cystitis or malignant bladder disease acted as a control group. Immunofluorescent staining of the biopsies was performed using monoclonal antibodies to the T-cell markers CD4 and CD8, and to CD14 (monocytes), CDw15 (granulocytes), CD19 B-cells (Pan-B), CD68 (macrophages) and HLA-DR. Anti-KLH antibody-producing plasma cells were detected using a standard technique. A semiquantitative analysis of locally infiltrating cell types was performed.

RESULTS: After treatment with KLH the increase of CD8+ suppressor cells was less pronounced than that of CD4+ helper cells. The T-helper/inducer to T-suppressor/cytotoxic cell ratio thus altered from 0.8:2.0 before treatment to 1.6:2.3 afterwards. Hence, the number of T-helper cells had increased considerably, whereas there was only a moderate increase in the number of T-suppressor cells. This cellular ratio could be detected for 9 months after KLH therapy. The numbers of activated HLA-DR+ immune cells in the submucosa and among urothelial cells also increased after KLH instillation. The degree of mononuclear cell infiltration of the submucosa increased considerably, but granulocyte infiltration was only moderate. Lymph follicles with enhanced B-lymphocyte counts were also detected.

CONCLUSION: Immune-cell infiltration into the urothelium and enhanced activation (expression of class II antigens) suggests distinct processes of cellular antigen recognition, which could be detected for up to 9 months after the beginning of KLH therapy. This may represent a basic functional mechanism of KLH therapy.